And as I've suggested elsewhere, there is something about Rey, something bigger than we know with her connection to the Force. I hope JJ takes the time to explain it in IX. I really do, because I do think its important. And if, to some, that continues her being a Mary Sue... so be it.
And that is ultimately where we shall split. I have no faith that JJ has anything planned that is greater for Ray and no explanation. He is a fan of mystery boxes. Ray is thus. Some hand waving and a growing sense of something going on and no plan as to anything more than that.